Still hate me, Princess?
by bellaBBblack
Summary: And suddenly three years of sexual tension, repression, of fighting and arguing with his step-sister, and a year fantasizing about what almost happened comes rushing to a climax.
1. Chapter 1

Frozen.

That is Derek's current state of being. His eyes locked on her long wet hair clinging to her soft looking skin, her face turned up towards the water, one hand braced on the tile wall in front of her, the other hand moving in a slow rhythm between her—

Oh. GOD. Is she-? She is. She's touching herself. And suddenly three years of sexual tension, repression, of fighting and arguing with his step-sister, and a year fantasizing about what almost happened _that_ night have all come rushing to a climax, depriving him of his self-control, voiding him of conscious thought, and making him unable to look or move away.

Casey bites her lip, lets out a little moan and her fingers move faster.

He can't take this. What the fuck is she doing taking a shower at one in the morning for anyways? And why is the shower curtain not all the way closed? He suddenly feels like a fucking pervert as he stands there watching his step-sister—HIS GODDAMN STEPSISTER WHO HE CANNOT UNDER ANY CIRCUMSTANCES PUSH UP AGAINST THE SHOWER TILES AND—

No. This is so fucked up. And wrong. And—

Derek groans and Casey's head snaps up. Her blue eyes widen at the sight of him. And when her eyes flicker down and widen more, he knows she is focusing on the very obvious bulge straining against the thin fabric of his boxers.

Her eyes snap back up to his and there is a very long, very awkward silence as they both stand there unmoving, not even blinking.

And it's too much. Casey hates Derek. But she can't help that for the last several months—and just moments ago in the shower—she's been actively fantasizing about her step-brother.

Ever since that night last summer.

It was late, they had been watching a movie with the family, but everyone else had already gone to bed, leaving the two of them, alone and smashed together on the couch. Without thinking—or planning, or over-analyzing, or any other very Casey-like thing—she laid her head on his shoulder.

And a new and good feeling suddenly tingled all over her body when she caught a whiff of his scent—_what is that anyways? Is it cologne or aftershave mixed with what? Boy sweat? Why is that so attractive? Goddammit, why is he so sexy_? — and felt his body heat so close to hers. Lust and desire. That was the new feeling. And it was overwhelming. And confusing since this was Derek. And she hated him.

When she chanced a glance up, she gasped. Their eyes had locked and she realized he'd been staring at her. His dark eyes flickered once to her lips. He leaned forward, almost imperceptibly. Casey let out a shriek and bolted upstairs.

They spent the next several days avoiding each other. She went back to Queens early, giving her mother some lame excuse about studying even though the semester was starting for two more weeks.

This time he's the one who runs away. Casey stands there shivering for several long minutes. Her friend from college, Samantha, had told her "Just do him and get it over with already!"

And right now, that's all she can think about. It's not like she has feelings for him. And it's not like anyone would find out or have to know.

That's all it takes. Her normal self has lost control. She turns off the water, towel dries her hair. She wraps the towel around her body and walks straight into Derek's bedroom.

She finds him, with his back to her, hovering over his dresser, and knuckles white against the edge. Without a word or a sound, she pads her way across the room, drops the towel and presses herself against his back. She wraps both arms around his waist.

"Casey, what the—" he stammers. Her hand smooths over his hard abs and beneath the waist band of his boxers. She's nervous. _God, please don't let him notice my shaking hand._

He tries to protest, but just groans when her hand wraps around him and strokes him ever so lightly. "Casey, we...I can't...oh god...we—"

"Shhh," she coos, standing on her toes and kissing his neck. She's really not sure where this sudden confidence is coming from, but it has to be at least partly from the intense desire thrumming in her veins.

Casey grabs his hand and places it between her legs. He groans as his fingers sink into her soft wet warmth. A second later, he spins her around and sits her atop his dresser, a question in his eyes. He doesn't remove his hand though. Instead his fingers plunge deeper into her.

"Derek," she moans. "Derek, I hate you."

He smirks. It's the first Derek-like reaction since he caught her in the shower. It sends a thrill through her. He lifts an eyebrow for her to continue.

"But I need you to—"

She stops, tilts her head back, and bucks her hips against his hand.

"Need me to what, Princess?"

He presses his thumb against her firmly, and curls his fingers, pumping harder and faster. Before she can answer, her whole world explodes. It's the most out of control he's ever seen her. And it's so fucking sexy he just wants to—

He removes his fingers, grabs her face and crashes his lips to hers. Derek carries her to the bed and in under a minute he's inside her. He moves slowly at first, then faster and harder as she cries for more.

And all he can think is _finally._ He collapses on top of her breathless, feeling drunk or high. But better.

"I still hate you," she murmurs against his neck. He chuckles.

After a minute, Derek rolls over, pats her on the butt, with a wide shit-eating grin on his face, "Go to bed, Princess."

She scowls, he winks. Casey huffs and marches off to her room.


	2. Chapter 2

It's June. She can't make up an excuse to go back to Queens. Hell, she's not even sure she wants to.

What she really wants is to slap that stupid smug smirk off Derek's face. Or kiss him. He's taunting her. His eyes are dark and heavy, his hair mussed. He _looks_ like he's been rolling around in bed with a girl. Even though she is ninety percent sure that isn't true. It's been three days since their little tryst in his bedroom.

She narrows her eyes at him. He grins.

_Oh fuck! Did he even come home last night? Who was he with? Are those the same clothes? Oh fucking—_

She practically throws her cereal bowl in the sink and storms out of the room. She hates him even more.

Casey grabs the keys to the Prince, smirking to herself, and bolts from the house.

It's ten o'clock at night when she returns. She not really surprised to find the rest of the family already in bed. Her mom and George always go to bed early. And Lizzie and Edwin are both gone. Marti's been asleep—or at least pretending to be (she is a Venturi)—for at least an hour.

And Derek's gone.

She's hot mess of emotions over this little fact. She's not even sure why she cares. She's certainly not going to admit to herself that she's possibly jealous or disappointed. Part of her is dying to let out all this tension with a good fight. The possibility that it could turn into another steamy romp in his bed, fills her with lust and trepidation and anger.

Because she hates Derek! And now he's seen her naked. Been _inside _her!

And all she can think about is how she wants it to happen again. She should not want this. It's wrong on so many levels. But the thought of him dragging his tongue along her collarbone, his hands gripping her ass as he—

_Fuck it, _she thinks.

Casey rummages through her dresser until she finds the laciest, sexiest pair of underwear she owns. Then she finds his practice jersey from high school hockey and pulls it over her head. She sneaks into his room to wait for him to come home, telling herself this doesn't mean anything. It's just sex.

With her unfairly very _very_ sexy step-brother. _Oh god, I'm going to hell._

After two hours, she falls asleep.


	3. Chapter 3

"D, what the hell is wrong with you?" Sam plops down on the couch next to him. Derek tilts his beer bottle back to his lips and takes a long pull. He's not even sure how to answer that.

Truth is, he's thought of nothing else but his step-sister, and the way it felt to kiss her, to be _inside_ her, for days. And damn, he just wants to figure out how to get back there.

He glances at Sam—his best friend, and Casey's ex—and blurts, "Did you and Casey ever have sex?"

Sam's eyes are wide and incredulous. He chokes on his beer. When he recovers, he says, "You did not just ask me that, did you?"

And really, right here, Derek should make some lame joke or a witty sarcastic remark, only he can't come up with anything. _Great, she's officially fried my brain._

So he just stares at Sam, because damn, he suddenly really needs to know this.

Sam squints, like he's trying to figure out a puzzle. After a few moments, his eyes light up, his eyebrows are practically in his hairline, and a smirk tugs at the corner of his mouth.

"Nah," he says, then adds as he turns his eyes away and just before he sips his beer, "She never shut-up about you long enough for that to happen."

Derek grins. He tries to suppress it, but fails miserably. He can't help it. Sam chuckles, slaps Derek on the back and says, "D, man, I don't even know if I want to know...but if you're asking me that question, what the fuck are you doing here?"

Derek smirks, and takes another long swig of beer before answering. "What time is it?"

"Midnight," Sam replies. Derek finishes his beer, places it on the table in front of them and stands.

"See ya later, Sammy," he says as he starts walking away. Sam laughs.

"Where ya going, D?" Ralph shouts as he passes by. Derek turns, meets Sam's eyes briefly and then turns back to the door.

"To see if she still hates me."

~000~

Back at home, Derek barges into Casey's room, only to find it empty. In fact, her bed is still made. A surge of possessiveness and jealousy rises up inside him. Followed quickly by anger.

_Fuck._ He's supposed to hate Casey. He's not supposed to be obsessing over his keener stepsister.

He trudges back to his room, contemplating how the fuck he's supposed to stop thinking about her.

He walks in and drops unceremoniously down onto his bed. A very feminine squeal sounds. Derek's eyes widen when he looks behind him. Casey, looking oh-so-sexy with her rumpled brown hair and hooded eyes is sitting up in his bed. He looks down, his eyes widen, and he yanks the covers off her.

"Der-ek!"

_Fuck me_, he thinks. She's wearing his practice jersey from high school. And nothing else. He can tell because it rides up, exposing her long legs and a tiny pink scrap of lace. _Holy fucking shit._

"Casey," Derek groans. "What are you doing?"

She blushes. Bright pink spreads across her cheeks. _Damn, I just want to—_

He doesn't wait for an answer. Instead he lunges, arms wrapping around her waist, his lips crashing against hers. The momentum sends them backwards. Derek's on top of her, his hands glide up her long smooth legs, slide under her panties and grab her ass.

Casey moans against his lips, and bucks her hips up, searching frantically for that delicious friction. Derek's lips leave hers, trailing not wet kisses down the column of her neck.

In under two minutes, he's naked. He pushes her shirt up, just enough so that he can slide her pink panties down. Casey goes to remove her shirt, but his hands stop her.

Derek leans forward to whisper in her ear, "No, Princess, leave it on."

She shivers. She can help the goose bumps that erupt along her flesh or the sudden gush of warmth and wetness his words cause.

Apparently he notices.

Derek's fingers slide down her stomach to touch her _there._

"Fuck," he groans. "You're so wet for me."

His hands start moving in teasing, torturing circles. Faster and faster, until she sees bursts of white streak across her vision. Before she can return to conscious thought, he sinks inside her.

Something shifts.

He lifts his head from her neck and meets her eyes. He starts moving, slow and steady. His desperation has waned. His frenzy desperate need for her morphs into something else.

The intensity of his dark eyes is too much. Casey grabs his face and crashes his lips to hers. Derek groans and hooks her leg over his elbow as he continues his slow pace.

Eventually she cries out and he falls over the edge a moment later, burying his face against her neck.

Neither one of them moves for a long silent minute. He doesn't want her to leave. Not like last time. He wants her stay, to sleep here. To let him hold her naked body against his.

_God, I sound like a fucking girl._

He rolls off her, lying on his back, staring at the ceiling. _What the fuck is going on here? What's happening? What are they doing?_

Ten minutes pass. Then twenty.

Casey huffs, "God, I really hate you," and then gets up to leave.

Derek grabs her wrist. "Stay, Princess. Hate me all you want, just stay."


	4. Chapter 4

So she stays.

It's a little bit awkward at first. Casey slips back under the covers and turns onto her side—away from Derek. He only hesitates briefly before wrapping an arm around her middle and pulling her against his chest.

And they fit. Perfectly.

This thought is disconcerting to Casey. She hates Derek. He's smug and arrogant. He thinks he's God's gift to women. Casey stops right there, and feels her cheeks warm. She can't even deny this. Because, even with her lack of experience, she's pretty certain Derek is really good in bed. He's so different than how she thought he would be. It's intense, having all his attention suddenly focused on her. He's attentive and vulnerable and it's…a feeling she can't quite describe, except it's _too much_.

She can't sleep. She starts thinking about other things. Things that's she's always liked about Derek. He's funny, and can be really thoughtful (even if he'd never admit it). She keeps thinking about Derek's kisses. His warm strong arms wrapped around her. How passionate he is. The intensity that has always brewed between them has suddenly started to morph into something else. Something new and scary and different.

She's freaking out. She cannot—_under any circumstances_—fall for Derek Venturi.

Casey tries to move, but Derek's arms are heavy with sleep. She pushes against his arm that's draped across her midsection harder, and tries to wiggle free.

"Derek," she whispers. She can tell her voice is all wrong. It all squeaky and high and breathless with panic.

He still doesn't budge.

"Derek," she says louder. He grunts and pulls her closer, burying his face in her neck.

Tears start to prick her eyes, and that familiar burn flames to life in her throat.

"Derek," she begs, louder as she chokes back a sob. She can't breathe. "Please, let me go."

She pushes again, and manages to wiggle free, but before she can get away from him, he wakes up.

"Casey?" he asks. His eyes are barely open, but he can see the tears that start to fall. He reaches for her, draws her trembling frame into his chest. As much as she was trying to get away from him before, she puts up no resistance now.

He doesn't say anything else. Doesn't asks what's wrong.

He already knows.

But it's not like he has any idea what to say. Truth is, he's been fighting his feelings for Casey for years. But despite what he feels or she feels or whatever this is that's growing between them, she's his step-sister. They share a _family._

This is not supposed to happen. This _can't_ happen.

He tries, he really does, to find the ability he used to have to push her away. To say something mean. But he can't. It's like he's lost that somewhere in the last week. He doesn't know how to build those walls back up. So he holds her. All night. Her tears finally stop, her breath evens out, and she falls asleep in his arms.

And he tries to figure out how he's ever going to be able to let her go.


	5. Chapter 5

At 8am, Derek slips out of bed. Casey is still fast asleep, but she's kicked the covers off, exposing her long shapely legs. Derek's jersey has ridden up, too. She's laying on her stomach and it's almost too much to ask him to walk away.

_Damn, she's so sexy,_ he thinks.

He's tempted to get back in bed, to kiss her neck, to wake her up and make love to her again.

_Whoa. What?_

Casey's head turns and he sees the tear tracks on her cheek.

He bolts. _This is so fucked up_, he thinks. _I cannot be in love with Casey. My stepsister._

Even as he thinks the words, he knows, somewhere deep, nothing's ever been more true. It's not even like it's a recent thing. Acting on it, yes. But wanting Casey, her being the exception to every rule he's ever had. No. That's _always_ been true.

Wearing nylon basketball shorts, his tennis shoes and an oversized Queens's sweatshirt, he jogs to Sam's house.

He decides to skip the front door. He cannot talk to Sam's mom right now. She's nice and he's usually pretty charming with moms, but right now he feels too raw and ragged to muster up any amount of charm.

So he finds Sam's downstairs window unlocked and slips inside.

"Sam," he says loudly right next to his ear. Sam jolts awake. Groggy and disoriented he stares at Derek for several seconds, taking in his current state.

"D," he croaks. "What the hell, man?"

"I need to talk to you. Get up."

Sam would normally tell Derek to go fuck himself for waking him up this early. But he can tell something's wrong. Derek's eyes are wild and serious. There's no signature smirk, no arrogant attitude. In fact, he looks desperate. Panicked.

So Sam gets up, dresses in his running clothes and follows Derek back out the window. They've walked about four blocks to the park, when one of them finally speaks.

"I think I'm in love with her, Sam."

Sam snorts.

Derek ignore this.

"I _made_ love to her last night."

Derek's having word vomit. He has to say this out loud. But honestly, he's surprised Sam didn't already know. It feels like it should be tattooed on his skin. She's changed everything.

Sam's eyes widen. He's a little bit surprised at this. Because it's Casey. She's not someone that takes sex lightly, and wouldn't let it happen without a commitment first.

And he's pretty sure Derek's never really made a commitment—at least not the kind Casey wants—to anyone. Not even Sally.

"I don't know what to do, Sammy." He stops, turns to his friend. "She was crying, and I—"

Derek cuts off. He doesn't do tears, but last night he did. He held her, he kissed her hair. He wanted nothing more than make her tears go away.

"And, what D? What are you going to do? Casey—"

"I don't know!" he yells. "Don't tell me what Casey deserves. I know, alright. But how can I give that to her? She's my stepsister! What about our family?"

"What about them? They're your family. They'll love you guys regardless. Sure, it may be a little weird at first, but y'all aren't really related. And—"

Derek deflates, and sits on a park bench. "Maybe none of this matters. Casey will never go for it. It goes against her perfect little plan."

Sam slaps Derek on the back. "Just talk to her. Be honest, tell her how you feel."

Derek gives him a skeptical look. Sam laughs.

"You're _The_ Derek Venturi. Find a way to convince her."


End file.
